1. Field of the Invention
The invention relates to magnetic fluid seal systems and methods for making the same.
2. Description of the Known Art
During operation of magnetic fluid seals, it has been long observed that microbursts of gas emanate from the magnetic fluid seal into the low-pressure vacuum as the rotation of the magnetic fluid seal is started and stopped. This microburst effect, also known as ‘burping’, results from gas trapped within each seal annulus of the magnetic fluid seal whose pressure exceeds the individual stage gas pressure retention capability. As the rotation of the magnetic fluid seal is started and stopped, the dynamic characteristics of the magnetic fluid seal change slightly, allowing some of the trapped gas to escape into the low-pressure side of the magnetic fluid seal and into the evacuated volume, undesirably raising its overall pressure.
Additionally, in some applications of magnetic fluid seals, it is acceptable to construct the seal by assembling from an atmosphere side. Other applications impose constraints that require the seal to be assembled from a vacuum side. The latter case tends to impose substantially greater difficulties in controlling the final distribution of fluid within the seal assembly.